Abstract: An ultrasonic actuator may be provided in which generation of a stress is prevented in the connection face of the piezoelectric element between the electrodes and the conductive members. The ultrasonic actuator includes a piezoelectric element (P1) and flexible cables (F1). The piezoelectric element (P1) includes: a piezoelectric layer (1); a power supply electrode (2) provided on a principal surface of the piezoelectric layer (1); a counter electrode (3) provided to face the power supply electrode (2) with the piezoelectric layer (1) interposed therebetween; a power supply external electrode (4) which is provided on a short-side surface of the piezoelectric element (P1), and is electrically coupled to the power supply electrode (2); and a counter external electrode (5) which is provided on a short-side surface of the piezoelectric element (P1), and is electrically coupled to the counter electrode (3).

Abstract: A drive unit includes an ultrasonic actuator, which has an actuator body formed using a piezoelectric element and outputs a driving force by vibration of the actuator body, and a control section which induces vibration in the actuator body by supplying a plurality of AC voltages to the piezoelectric element. The control section provides, in combination, phase control, which controls the driving force by adjusting a phase difference between a first and a second AC voltages, and wave-number control, which controls the driving force by adjusting the wave number included in a predetermined burst period in each AC voltage.

Abstract: A drive unit includes an ultrasonic actuator having an actuator body formed using a piezoelectric element, and a driving element provided on the actuator body and configured to output a driving force by moving according to the vibration of the actuator body, and a control section configured to induce the vibration in the actuator body by applying a first and a second AC voltages having a same frequency and different phases to the piezoelectric element. The control section adjusts the first AC voltage and the second AC voltage so that the first AC voltage and the second AC voltage have different voltage values from each other.

Abstract: The drive efficiency of a vibratory actuator is improved without increasing a weight of a driver element. An ultrasonic actuator (2) includes an actuator body (4) for generating longitudinal vibration and bending vibration, and driver elements (8), provided on a mounting surface (40a) which is one of side surfaces of the actuator body (4), for making an orbit motion according to the vibrations of the actuator body (4) to output driving force. In the driver element (8), a through hole (80) is provided.

Abstract: A vibratory actuator is provided in which a movable body can be stably driven even when a groove is formed in an abutment body by the friction between the driver element and the abutment body. An ultrasonic actuator (2) includes an actuator body (4) which performs a longitudinal vibration and a bending vibration, and a driver element (8a, 8b) which is provided on one of side surfaces of the actuator body (4) which is a mounting surface (40a), and performs an orbital motion in accordance with the vibrations of the actuator body (4) to output a driving force. The driver element (8a, 8b) includes a first driver element (8a) and a second driver element (8b) which are provided on the mounting surface (40a) at different positions in a longitudinal direction of the actuator body (4). The first driver element (8a) and the second driver element (8b) are located at different positions in a thickness direction of the actuator body (4).

Abstract: An ultrasonic actuator includes: an actuator body (5) including an actuator body (50); a control circuit (150) for setting a driving frequency; power supply sources (191, 192) for applying a driving voltage having the driving frequency to the actuator body; and a memory (170) for storing data related to a difference between antiresonance and resonance frequencies of the actuator body (50). The control circuit (150) determines, based on a reference frequency where a current value of a current fed to the piezoelectric element (50) is local minimum and the data stored in the memory (170), a lower limit of a control range of the driving frequency so that the lower limit is equal to or higher than a frequency where the current value of the current fed to the piezoelectric element (50) is local maximum and determines the driving frequency to be a frequency in the control range.

Abstract: An ultrasonic actuator (3) includes an actuator body (4) performing a plurality of vibrations including a bending vibration, and a driver element (5) which is attached to a long side surface (40b) of the actuator body (4), and outputs a driving force by making an orbit motion in response to the vibrations of the actuator body (4). The driver element (5) is provided with an attachment surface (51), and is attached to the long side surface (40b) with the attachment surface (51) in surface contact with the long side surface (40b). A width of the attachment surface (51) in the longitudinal direction of the long side surface (40b) is smaller than a maximum width of the driver element (5) in the longitudinal direction of the long side surface (40b).

Abstract: A drive unit includes a control unit for controlling an ultrasonic actuator. The control unit performs switching between a normal operation mode in which the piezoelectric element unit vibrates at a frequency close to a resonance frequency of longitudinal vibration in the lengthwise direction of the piezoelectric element unit and a resonance frequency of bending vibration to let the ultrasonic actuator output a driving force and a heating mode in which the piezoelectric element unit vibrates at a frequency close to a resonance frequency of longitudinal vibration in the thickness direction of the piezoelectric element unit to heat the piezoelectric element.

Abstract: An ultrasonic actuator (3) includes an actuator body (4) performing a plurality of vibrations including a bending vibration, and a driver element (5) which is attached to a long side surface (40b) of the actuator body (4), and outputs a driving force by making an orbit motion in response to the vibrations of the actuator body (4). The driver element (5) is provided with an attachment surface (51), and is attached to the long side surface (40b) with the attachment surface (51) in surface contact with the long side surface (40b). A width of the attachment surface (51) in the longitudinal direction of the long side surface (40b) is smaller than a maximum width of the driver element (5) in the longitudinal direction of the long side surface (40b).

Abstract: A drive unit includes a vibration actuator for controlling the piezoelectric element. A control section controls the vibration actuator switchably between a normal operation mode in which the piezoelectric element vibrates at a predetermined frequency to let the vibration actuator output a driving force, and a heating mode in which the piezoelectric element vibrates in a direction perpendicular to a direction of the driving force at a frequency different from the frequency in the normal operation mode to heat the piezoelectric element.

Abstract: A drive unit includes a guide, a stage which is movable relative to the guide, an ultrasonic actuator for moving the movable body and a control unit for controlling the ultrasonic actuator. The ultrasonic actuator includes a driver element in contact with the stage and is fixed to the guide. A surface of the stage in contact with the driver element is an undulating surface. The control unit detects the position of the stage based on a change in contact pressure on the driver element due to the undulating surface.

Abstract: An ultrasonic actuator includes: a piezoelectric element 10 for generating various kinds of vibrations having different vibration directions; a driver element provided on the piezoelectric element 10 and actuated in accordance with the vibration of the piezoelectric element 10 to output driving force toward a certain driving direction; feeding electrodes 8 provided on the piezoelectric element 10 and electrically connected to the piezoelectric element 10; and feeding-supporting parts 6A, 6B, 7A, 7B and 9A abutting the feeding electrodes to elastically support the actuator body and serving as feeding terminals for supplying a voltage to the feeding electrodes 8.

Abstract: A drive unit (1) includes a stage (3), a first ultrasonic actuator (4A) for driving the stage (3) in the X direction, and a second ultrasonic actuator (4B) for driving the stage (3) in the Y direction. In driving the stage (3) in only one of the X and Y directions, one of the first and second ultrasonic actuators (4A, 4B) corresponding to the one of the directions generates a composite vibration of a longitudinal vibration parallel to a contact surface of the stage (3) and a bending vibration orthogonal to the contact surface, while the other ultrasonic actuator generates only a longitudinal vibration parallel to the contact surface of the stage (3).

Abstract: An ultrasonic actuator includes: a piezoelectric element 10 producing stretching and bending vibrations; driver elements 2, 2 placed on the piezoelectric element 10 so as to be actuated in accordance with the vibrations of the piezoelectric element 10, thereby outputting a driving force; a case 12 for supporting the piezoelectric element 10; and wall-surface supporters 6A and 6B, top-surface supporters 7A and 7B and a bottom-surface supporting part 8 all placed between the case 12 and the piezoelectric element 10 to previously apply compressive forces to non-node parts of the vibrations of the piezoelectric element 10 along the directions of the vibrations.

Abstract: A piezoelectric element is formed by stacking piezoelectric layers and internal electrode layers. The internal electrode layers are positive and negative electrode layers. The positive electrode layers are first and second positive electrode layers. The negative electrode layers are first and second negative electrode layers. Each of the first positive and negative electrode layers includes four divided electrodes and a connecting electrode for connecting a pair of the four divided electrodes formed on diagonally opposite two areas along a first diagonal direction on a principle surface of the associated one of the piezoelectric layers. Each of the second positive and negative electrode layers includes four divided electrodes and a connecting electrode for connecting a pair of the four divided electrodes formed on diagonally opposite two areas along a second diagonal direction on a principle surface of the associated one of the piezoelectric layers.

Abstract: Internal electrode layers (5) include a common electrode layer (3) and feed electrode layers (6) alternately placed in a stacking direction with piezoelectric layers (1) interposed between the common electrode layer (3) and the feed electrode layers (6). The common electrode layer (3) has a common electrode (3a). The feed electrode layers (6) include a first feed electrode layer (6a) and a second feed electrode layer (6b). The first feed electrode layer (6) has four divided electrodes (2a through 2d) and a first connection electrode (2e) for providing connection between two of the divided electrodes (2b, 2d). The second feed electrode layer (6) has four divided electrodes (4a through 4d) and a second connection electrode (4e) for providing connection between two of the divided electrodes (4a, 4c).

Abstract: A drive unit (1) includes a stage (3), a first ultrasonic actuator (4A) for driving the stage (3) in the X direction, and a second ultrasonic actuator (4B) for driving the stage (3) in the Y direction. In driving the stage (3) in only one of the X and Y directions, one of the first and second ultrasonic actuators (4A, 4B) corresponding to the one of the directions generates a composite vibration of a longitudinal vibration parallel to a contact surface of the stage (3) and a bending vibration orthogonal to the contact surface, while the other ultrasonic actuator generates only a longitudinal vibration parallel to the contact surface of the stage (3).

Abstract: In driving a target body only by one of actuators, the target body is smoothly driven. A drive unit (1) includes a stage (3), a first ultrasonic actuator (4A) for driving the stage (3) in an X direction and a second ultrasonic actuator (4B) for driving the stage (3) in a Y direction. When the stage (3) is driven only in one of the X direction and the Y direction, one of the first and second ultrasonic actuators (4A and 4B) which corresponds to the direction generates composite vibration of longitudinal direction parallel to a contact surface of the stage (3) and bending vibration perpendicular to the contact surface of the stage (3). On the other hand, the other one of the first and second ultrasonic actuators (4A and 4B) generates only longitudinal vibration parallel to the contact surface of the stage (3).

Abstract: An ultrasonic actuator (3) includes an actuator body (4) performing a plurality of vibrations including a bending vibration, and a driver element (5) which is attached to a long side surface (40b) of the actuator body (4), and outputs a driving force by making an orbit motion in response to the vibrations of the actuator body (4). The driver element (5) is provided with an attachment surface (51), and is attached to the long side surface (40b) with the attachment surface (51) in surface contact with the long side surface (40b). A width of the attachment surface (51) in the longitudinal direction of the long side surface (40b) is smaller than a maximum width of the driver element (5) in the longitudinal direction of the long side surface (40b).

Abstract: An ultrasonic actuator includes: an actuator body (5) including an actuator body (50); a control circuit (150) for setting a driving frequency; power supply sources (191, 192) for applying a driving voltage having the driving frequency to the actuator body; and a memory (170) for storing data related to a difference between antiresonance and resonance frequencies of the actuator body (50). The control circuit (150) determines, based on a reference frequency where a current value of a current fed to the piezoelectric element (50) is local minimum and the data stored in the memory (170), a lower limit of a control range of the driving frequency so that the lower limit is equal to or higher than a frequency where the current value of the current fed to the piezoelectric element (50) is local maximum and determines the driving frequency to be a frequency in the control range.